Apparatus for locating binding areas around well casing



Jury 22, 1952 R. B. BAsHAM ErAL APPARATUS FOR LocATlNG BINDING AREAS AROUND WELL. cAsNG Filed Aug. 25, 1948 PICK- vIBRAToR RECORDER FILTER AMPLIFIER Patented July 22, 1952 APPARATUSFOR LooA'rING BINDING AREAS AROUND WELL oAsING Raymond B. Basham andfCharles Wall/lacune, Fort WVorth, Tex., assignors to Westronics, Inc., Fort Worth, Tex., a corporation of Texasl Applicatie!! August 25, 194s. seri-ai No. 46,146

1 o This invention relates to a method and apparatus for locating frozen or bound areas ofpi'p'e or well casing beneath the earths surface. Generally, the invention has to do with recovery of casing from abandoned wells, and has particular reference to locating areas around the casing v which have become frozen or bound-by the presence of cement therearound, lateral lshifting of the earths formations resulting in pressures applied to the outer surface of the casing, or the caving of the well formations wherein rocks form wedges against the casing surface. Such freezing or binding prevents the withdrawal of the casing, and it then becomes necessary to sever the cas- Ying above the bound area. The severing operation is performed by explosive means such as radial j et severing recently introduced to the art.

An object of the invention is to provide a method and means for accurately locating frozen or bound areas of Well casing below the earths surface.

Another object of the inventionis to measure vibration variations Within a'r relatively short length of well casing for determining thelocation of bound casing areas, thereby avoiding dissipa= tion of the vibrations as occurs when traveling through the mass of long lengths 'of casing.

A further object of the invention is to provide vibration energy longitudinally ofthe well casing for effectively measuring variations of amplitude to determine the presence of bound or frozen areas around the casing surface.

A further object of the invention is to locate frozen or bound areas of a casing in a well while raising and lowering the instrument for that purpose through the well casing.

A further object of the invention isto provide a method and means oflocating casing couplings and the like which cause'an increase in effective mass around said casing.

The invention is comprised of a vibrator of known frequency and a vibration pick-up arranged in spaced relation with respect to each other and in sliding contact with the inner surface of the casing to be computed for locating frozen or bound areasV therearound. Modified forms of the-invention may be made whereinthere is'no actual contact of the apparatus with the inner ferred. The vibrator andpick-up are suspended in the casing by means of a cablewhich also 'carries electrical leads from the pick-up to the earths surface Where they are connectedwith recording or other suitable indicating means. When vibration energy is transferred'frornthe vibrator tion thereagainst.

to the well casing, the amplitude passing longitudinally through the casing wall will have an attenuation proportional to the distance from the vibrating source, and will also have amplitude variation due to the various types of formation Vin contact with the outside of the casing. For example, if the'outside of the casing is bound with cement, or is in a tight impacted formation, the amplitude in the affected length ofcasing will be 'less than that of a loosely packed formation.` By

moving the vibrator and its contacting assembly through the casing, ascending or decending, or while standing still, a change in longitudinal vibration amplitude will occur at the frozen. area, the amplitude being-diminished by theincrease in the effective mass of casing and adjacent formal-B'y using a vibration pick-up, 'the variation of amplitude maybe measured in the length of casing between the casing contacts of the vibrator and the casing contacts of the vibration pick-up. A pick-up spaced less than one-quarter Wave length from `the vibrator will provide a reasonably short distance between the said units so as to prevent nodal'po'ints from appearing between the same when in operation. `By energizing the vibrator, transferring the vibration energyl to the casing; and determining variations of amplitude reaching the vibration pick-up, and by knowing the relative height of the'apparatus within the `well casing, the locations of frozen areas about the'well casing may be determined. The pick-up may be tuned tothe frequency of the vibrator so as to exclude extraneous vibrations. However, a

tuned electrical filter maybe used for the last preferred that the buzzer or vibrator bedisposed in a direction to impartllongitudinal vibrationsalong the length of affected casing.' i-

Y. Anembodiment-of theinvention is illustrated lin` the accompanying drawing, wherein:

- fEgure lis a vertical sectional' View of a length ofV casing in Van earth formation, and showing vbroken sectional and elevational views of the 'Vibrator I assembly Y. vand pick-'up assembly sus,- lpended therein. Y

Figure 2 is a lateral sectional view taken on lines 2-2 oi' Figure 1. v

Figure 3 is a broken longitudinal sectional view of a portion of the Vibrator assembly and particularly showing means for imparting longitudinal vibration energy to the casing.

Figure 4 is a block diagram villustrating an arrangement for recording variations of vibration amplitude in the casing between the vibrator and the pick-up.

The casing I 0, illustrated in Figure 1, is shown bound by cementl II below the earth iformation I2. The apparatus for locating such bound areas of casing includes a vibratorassembly I3 including a cylindrical housing I4, radially .extending upper and lower arms I5 secured to the said housing, and skids I6 slidabl-y mounted on vand extending beyond the ends of the said arms. The skids I6 are parallel with the axis of the casing I and are in contact with the inner wall of the latter by reason of compression springs I'I mounted on the arms Iv between the housing I4 and the said movable skids.

Within the vibrator housing I4 a -source "of electrical power is provided in the form of a dry cell I8 and is electrically connected with a vibrator head I9 mounted in the upper end of the said housing, Details of an exemplary vibrator head I9 are shown in `Figure 3 and include a coil 20, a contact arm 2|, and an armature 22 mounted on a diaphragm 23 between the said coil and the said arm. It will be noted from the drawing that the axial 'centers of the coil 2Q, the armature 22, and the contact 24 of the 'arm-2 I .are inftheaxial center-of thehousing I4, Which,in.turn, is With- 1 `in the axial vcenter ofthe vcasing I0. The coil 2G is mounted on a cylindrical support 25 having 'an upper iiange 26 which rests upon an internal flange 21 formed in the inner-wall of the housing I4. The diaphragm 23 rests upon the flangeA 25 of the support 25 and is retained by means 'of-a sleeve 28 slidably mounted in the upper'iend of the housing I4. A threaded'adapter 29 is engaged in the upper end of the housing I4 forv retaining the sleeve 28 against the diaphragm 23 and for vsupporting the entire vibrator assembly I3. An

eye 30 in the upper center of the adapter 29 is provided for carrying out the'supporting arrangement.

Above the vibrator assembly I3 there is another housing v3l, :similar to the rst referred to dially extending arms I 5,'outwardly slidable skids I6 at the outer ends thereof, and springs I1 besembly I3, but also serves `as 'a vibration lter between the vibrator head I9 and the pick-up'33. `The-upper end of the pick-up yhousing 3l is prolvided with an adapter 36 for engaging 'a -support- 4ring Acable V3'! extending to the earths surface. :Thercablie 3l 4alsoifsupport's thevelectric'al connections 38 extending; to "theY earths surface'whe're4 housing I4, which also includes the described ra- Y they are connected with a; band'pa'ss iilter, an

vamplifier, and a suitable record-er, respectively, asl shownin Figure 4.

. In operation, the assembly carrying'thegpick-'up 33 and the vibrator assembly I3 suspendedftheref '4 from, are raised or lowered through the well cas ing I0 with the skids I6 in sliding contact with the casing wall. By reason of the described construction of the vibrator assembly, longitudinal vibration energy is imparted to the casing I0 and the vibration amplitude is transmitted therefrom to the skids I6, arms I5, pick-up housing 3| and to the pick-up 33. The vibration imparted to the pick-up 33 is then converted into electrical energy 'and is transmitted to the earths surface through the leads 28 where it is filtered, amplied and recorded. The last three referred to devices are conventionaland need not be described in detail. It is also to be understood that any suitable in dicating means may be substituted therefor.

When the outer area of the casing IIJ, between the vibrator assembly I3 and the assembly including the pick-up 33, is bound or frozen, as by cement II, a corresponding attenuation of vibration in the said casing causes a variation of amplitude received at the pick-up 33 and registered at the recorder. When the described vassemblies are raised and lowered through the casing IB it will be apparent that readings may be taken or registered while the apparatus is moving, as well as when standing still.

The described form of the invention is not restrictive, but may be made in many ways within the scope of the appended claims.

What is claimed is:

l. Apparatus for locating a binding area around a well casing, comprising a vibrator having an .armature arranged for vertical operation and a pick-up spaced from each other in the well casing, means carried by said vibrator and said pick-up for contacting theinner wall of said casing, and an indicator connected with said pick-up for indicating variations of vibration amplitude in said casing between said vibrator and said pick-up.

2. Apparatus for locating a binding area around a well casing, comprising a vibrator having an armature arranged for vertical operation and a pick-up spaced from each other in the Well casing, contacts carried by said vibrator and said pick-up for contacting the inner wall of said casing, and an indicator connected with said pick-up for indicating variations of vibration amplitude in said casing between said .vibrator and the said pick-up.

3. Apparatus for locating ay binding .area around a well casing, comprisinga vibrator hav- .ingr anarmature arranged for vertical operation up mountedin the said pick-up housing, contacts mounted on both of said housings for contacting vthe innerwall of said casing, andan indicator connected with said pick-up :forv indicating variations 0I" vibration amplitude in said casing between said vibrator and said pickup. Y

5.'Appa`ratus for locating a binding area VVaround y,a Well casing, comprising a Vibrator housing, a pick-up housing spaced from the said vibrator housing, the said housings being connected for suspension within the weil casing by means of a Vibration ilter, radial arms secured to and extending from said vibrator housing. skids mounted on the said vibrator housing for contacting the inner Wall of said casing, a vibrator having an armature arranged for vertical operation mounted in said vibrator housing and disposed for imparting longitudinal vibration energy to the said casing. radial arms secured to and extending from said pick-up housing, skids mounted on the last said arms for contacting the inner wall of said casing, a pick-up mounted in said pick-up housing, and an indicator connected with said pick-up for indicating Variations of vibration amplitude in the casing between said vibrator and said pickup.

6. Appratus for locating a binding area around a well casing, comprising vibrator means and pick-up means spaced from each other in the well casing, means imparting initially longitudinally vibration energy from said vibrator to the said casing, means transmitting the imparted vibration energy from the casing to said pick-up, and indicator means connected. with said pick-up for indicating variations of vibra tion amplitude in the casing between said vibrator and said pick-up.

RAYMOND B. BASI-IAM.

` CHARLES W. MACUNE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,654,819 Kinley Jan. 3, 1928 2,156,052 Cooper Apr. 25, 1939 2,191,119 Schlumberger Feb. 20, 1940l 2,191,120 Slichter Feb. 20, 1940 2,200,476 Mounce May 14, 1940 2,233,992 Wyckoff Mar. 4, 1941 2,265,768 Athy Dec. 9, 1941 2,275,736 Cloud Mar. 10, 1942 2,277,110 Johnson Mar. 24, 1942 2,350,371 Smith June 6, 1944 2,455,940 Muskat et al Dec. 14, 1948 2,522,433 Dahlberg, Jr. Sept. 12, 1950 

